The present invention relates to an electric system for vehicles, an electric system having plural electric loads for supplying electric power commonly to the plural electric loads, and specifically to an electric power supplying apparatus and an intensive wiring apparatus for automotive vehicles.
Because various types of electric equipment are usually used in riding vehicles, many systems of electric power lines are used, for example, for supplying the electric power from the electric power apparatus, such as batteries and an electric power generator, to the electric load.
In recent years, especially for automotive vehicles, many kinds of electrical equipment are loaded in the vehicle, and their numbers are increasing remarkably. As a result, there may be an unfavorable case in which an increase in the number of equipment wires in the vehicle gives some constraint problems in applying this kind of system to a practical use.
For resolving this problem which has accompanied the increase in the number of equipment systems, what is often used is a so-called "line concentration and wiring system" which is a controller having a communication function and an arithmetic function for controlling the individual electric load, in which the control signal for the individual electric load is obtained by numerical calculation and the control signal so calculated is transferred to the terminal apparatus connected to the controller through the communication lines, and thus, some electric loads connected to the terminal apparatus may be controlled.
With this controller, the number of lines required for transmitting the control signals can be reduced, hence resolving the problems accompanied with the increase in the number of equipment systems.
As for these kinds of line concentration and wiring systems, for example, some systems in the prior art are disclosed in U.S. Pat. No. 4,771,382, U.S. Pat. No. 5,113,410, U.S. Pat. No. 4,855,896 and U.S. Pat. No. 5,438,506.
However, even in the case of applying this kind of line concentration and wiring system in the prior art, as the electric power to the individual electric load is supplied directly from the electric power line through the fusing fuse, the number of electric power lines is required to be equal or larger than the number of electric loads. Therefore, in the prior art systems, the individual parts in the vehicle such as the ceiling and floor of the cabin are usually filled with many electric power lines.
In the conventional electric power supply system for vehicles, what is generally used is a single-sided-grounded electric power supply method, in which the electric power supply lines from the electric power supply assume that one part of the vehicle body is used as one side of the electric power supply line. Therefore, in case any of the electric power supply lines accidentally contacts the vehicle body, a short-circuit abnormality occurs.
In order to solve this short-circuit abnormality, in the prior art electric power supply systems for vehicles, an independent fuse is installed for each individual electric load system, with which a designated electric load system may be protected by blowing the fuse when the electric power line gives a short-circuit in order to separate the electric load system from the electric power supply.
In the prior art systems, when the fuse is blown in accordance with the electric circuit abnormality and then, the operation of the corresponding electric load is interrupted, there may be caused such a problem that the safety feature of the whole vehicle system and the comfort feature in driving the vehicle may be partially disabled or fully lost.